I fully realize it can be frustrating to see a book priced unreasonably high but I respect anyone's right to set whatever price they want. No one has a responsibly (seriously, a responsibility?) to do anything and no one is forcing you to buy it. Historically, on this board, it's been frowned upon to 'threadcrap' in someone's sales thread. And complaining openly about pricing in their thread is threadcrapping.
However, the tone of this board has changed over the years but I still think that it's a richard move to to these things openly in a sales thread. Send them a PM or post in the thread shown below.